1. Field of the Invention
The present invention relates to an improvement of a programmable sequence control device (U.S. Pat. No. 4,167,788 and Japanese Examined Patent Publication No. 56-21171) that the present inventor has previously developed, and particularly to a general purpose programmable sequence control device simulating flow chart sequences capable of programming sequences by simulating flow chart sequences almost as it is and of controlling one stage flow chart in one clock time when the sequences are executed.
2. Description of the Related Art
The programmable sequence control device that the present inventor has previously proposed is composed of three terminals; one is a sequence signal output terminal S, a jump condition signal input terminal T and a jump destination signal input terminal R; those three terminals constitutes one set. Adequate number of sets are formed corresponding to a number of sequences. Logical function circuits are formed for determining logic values of the sequence signals in a stage in which each logical sum (OR) of each logical produce (AND) of the first and the second terminal signals in each set is a first variable, a logic value of the third terminal signal in the stage is a second variable, and a logic value of the first terminal signal in a preceding stage is a third variable. Input/output signal lines of the circuits are connected to the terminals corresponding to the aforementioned logics and required signal delay circuits are connected serially to the first terminal, thereby one set of the terminals can be corresponded to any execution stage of any sequence program, as shown in FIG. 1.
In case of programming, for example, a content of a flow chart shown in FIG. 2, each terminal is connected as shown in FIG. 3 in which a circuit is constituted in a hard wired logic system. This system is extremely convenience and understandable. However, corresponding to a hard size, the above-mentioned set numbers must be increased and an applicable scope is limited as a matter of course because the connections are required.
An object of the present invention is to provide a general purpose programmable sequence control device simulating flow chart sequences capable of programming sequences by simulating flow chart sequences almost as it is with a stored logic system, increasing no circuit corresponding to a number of the sequence stages and requiring no connections compared to that of the conventional wired logic system.